// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_MANIFEST_MANIFEST_MANAGER_HOST_H_
#define CONTENT_BROWSER_MANIFEST_MANIFEST_MANAGER_HOST_H_

#include <memory>

#include "base/callback_forward.h"
#include "base/id_map.h"
#include "base/macros.h"
#include "content/public/browser/web_contents_observer.h"

namespace content {

class RenderFrameHost;
class WebContents;
struct Manifest;

// ManifestManagerHost is a helper class that allows callers to get the Manifest
// associated with a frame. It handles the IPC messaging with the child process.
// TODO(mlamouri): keep a cached version and a dirty bit here.
class ManifestManagerHost : public WebContentsObserver {
public:
    explicit ManifestManagerHost(WebContents* web_contents);
    ~ManifestManagerHost() override;

    using GetManifestCallback = base::Callback<void(const GURL&, const Manifest&)>;

    // Calls the given callback with the manifest associated with the
    // given RenderFrameHost. If the frame has no manifest or if getting it failed
    // the callback will have an empty manifest.
    void GetManifest(RenderFrameHost*, const GetManifestCallback&);

    // WebContentsObserver
    bool OnMessageReceived(const IPC::Message&, RenderFrameHost*) override;
    void RenderFrameDeleted(RenderFrameHost*) override;

private:
    using GetCallbackMap = IDMap<std::unique_ptr<GetManifestCallback>>;

    void OnRequestManifestResponse(
        RenderFrameHost*, int request_id, const GURL&, const Manifest&);

    // Returns the CallbackMap associated with the given RenderFrameHost, or null.
    GetCallbackMap* GetCallbackMapForFrame(RenderFrameHost*);

    base::hash_map<RenderFrameHost*, std::unique_ptr<GetCallbackMap>>
        pending_get_callbacks_;

    DISALLOW_COPY_AND_ASSIGN(ManifestManagerHost);
};

} // namespace content

#endif // CONTENT_BROWSER_MANIFEST_MANIFEST_MANAGER_HOST_H_
